stop retrying for invalid selectors (such as "#a:b")

It does not make sense to retry the query for invalid selector
because it will always fail.

But the CDP hides the detail error for invalid selector, and only
gives us "DOM Error while querying". We will stop retrying when
we see this error message.

query.go

@@ -9,6 +9,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/chromedp/cdproto"
 	"github.com/chromedp/cdproto/cdp"
 	"github.com/chromedp/cdproto/css"
 	"github.com/chromedp/cdproto/dom"
@@ -189,7 +190,20 @@ func (s *Selector) Do(ctx context.Context) error {
 		}
 
 		ids, err := s.by(ctx, fromNode)
-		if err != nil || len(ids) < s.exp {
+		if err != nil {
+			var e *cdproto.Error
+			// When the selector is invalid (for example, "#a:b" or "#3"), it will
+			// always fail with "DOM Error while querying". It does not make sense
+			// to retry in this case.
+			// Maybe "DOM Error while querying" is also used for other errors other
+			// than invalid selector. But the response does not contain anything
+			// else that can be used to distinguish them. So we have to go with it.
+			if errors.As(err, &e) && e.Message == "DOM Error while querying" {
+				return true, err
+			}
+			return false, nil
+		}
+		if len(ids) < s.exp {
 			return false, nil
 		}
 		nodes, err := s.wait(ctx, frame, execCtx, ids...)

query_test.go

@@ -251,6 +251,36 @@ func TestRetryInterval(t *testing.T) {
 	}
 }
 
+func TestNoRetryForInvalidSelector(t *testing.T) {
+	t.Parallel()
+
+	ctx, cancel := testAllocate(t, "table.html")
+	defer cancel()
+
+	ctx, cancel = context.WithTimeout(ctx, time.Second)
+	defer cancel()
+
+	tests := []struct {
+		name    string
+		sel     string
+		by      QueryOption
+		wantErr string
+	}{
+		{`pseudo class`, `#a:b`, ByQuery, "DOM Error while querying (-32000)"},
+		{`leading number`, `#3`, ByQuery, "DOM Error while querying (-32000)"},
+		{`empty selector`, ``, ByQuery, "DOM Error while querying (-32000)"},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			var nodes []*cdp.Node
+			if err := Run(ctx, Nodes(test.sel, &nodes, test.by)); err.Error() != test.wantErr {
+				t.Fatalf("want error %v, got error: %v", test.wantErr, err)
+			}
+		})
+	}
+}
+
 func TestByJSPath(t *testing.T) {
 	t.Parallel()